http://forum.miata.net/vb/showthread.php?t=429587
I've never auto-x'd my green car (due to extreme manliness) but my 700/400lb spring AST set up is more comfy on the street than my daily on Bilstein HD's with stock springs (which is already comfy). The ride is firmer, but my track car definitely has better high-speed valving which helps translate into more comfort on the street.